Sparse inversion based migration velocity analysis method and device

Abstract

The invention discloses a sparse inversion based migration velocity analysis method. The sparse inversion based migration velocity analysis method comprises the steps of performing prestack depth migration according to seismic data and an initial velocity model to obtain a co-imaging point trace gather; picking up cophasal shaft residual depth in the co-imaging point trace gather and using the cophasal shaft residual depth as system input data; utilizing the residual depth and a velocity model to be calculated to establish a migration velocity analysis sparse inversion mode; utilizing a nonlinear iteration algorithm to solve a velocity mode; repeating execution till a shutdown rule is confirmed, and inversing a final migration velocity model. The invention further discloses a sparse inversion based migration velocity analysis device. By means of the technical scheme, the migration velocity model can be quickly inversed, multiple solutions can be decreased, and the sparse inversion based migration velocity analysis method and device have good application value on large-scale earthquake velocity modeling application.

Description

technical field [0001] The invention belongs to the field of exploration seismic technology, and relates to a migration velocity analysis method based on sparse inversion, and also relates to a migration velocity analysis device based on sparse inversion. Background technique [0002] The seismic prestack depth migration results are highly sensitive to the velocity model, which makes the velocity analysis method based on migration data a powerful tool for velocity modeling. In recent years, with the continuous improvement of the imaging accuracy of complex geological structures, the value of migration velocity analysis in the field of seismic exploration has become more and more important. From the perspective of inversion theory, migration velocity analysis is a nonlinear inversion problem, and elastic parameters are updated iteratively through two steps of prestack depth migration and velocity analysis. In each iteration of migration velocity analysis, it is necessary to ...

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Problems solved by technology

Migration velocity analysis is therefore a time-consuming and labor-intensive process

[0003] In practical applications, most of the migration velocity analysis models are objective functions constructed by least squares, which often makes the inversion results poor in stability and multi-solution, and the solution process is usually numerically solved by the linear conjugate gradient method, and there are iterative Disadvantages of under- or over-iterating

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